SCF-Fbxo42 promotes synaptonemal complex assembly by downregulating PP2A-B56

Meiosis creates genetic diversity by recombination and segregation of chromosomes. The synaptonemal complex assembles during meiotic prophase I and assists faithful exchanges between homologous chromosomes, but how its assembly/disassembly is regulated remains to be understood. Here, we report how two major posttranslational modifications, phosphorylation and ubiquitination, cooperate to promote synaptonemal complex assembly. We found that the ubiquitin ligase complex SCF is important for assembly and maintenance of the synaptonemal complex in Drosophila female meiosis. This function of SCF is mediated by two substrate-recognizing F-box proteins, Slmb/beta Trcp and Fbxo42. SCF-Fbxo42 down-regulates the phosphatase subunit PP2A-B56, which is important for synaptonemal complex assembly and maintenance.

Automated summary

Posttranslational modifications phosphorylation and ubiquitination cooperate to promote synaptonemal complex assembly, with the ubiquitin ligase complex SCF playing a key role by down-regulating the phosphatase subunit PP2A-B56. This regulation is mediated by F-box proteins Slmb/beta Trcp and Fbxo42, highlighting the importance of these proteins in maintaining genetic diversity during meiosis.